MCX was down 5% at Rs 507.05. Financial Technologies (India) (FTIL) hit a lower circuit limit of 5% at Rs 276.70.

Shares of FTIL had underperformed the market over the past one month till 7 May 2014, sliding 16.67% compared with the Sensex's 0.09% fall. The scrip had underperformed the market in past one quarter, rising 4.20% as against Sensex's 9.56% rise.

Shares of MCX had outperformed the market over the past one month till 7 May 2014, rising 4.10% compared with the Sensex's 0.09% fall. The scrip had, however, underperformed the market in past one quarter, rising 4.67% as against Sensex's 9.56% rise.

The Mumbai police's Economic Offences Wing (EOW) has arrested Jignesh Shah, chairman and group chief executive of FTIL, in connection with the Rs 5574.34 crore fraud at National Spot Exchange (NSEL).

Shah's arrest is the 10th and the most significant in the case since the crisis began in July 2013. FTIL owns 99.9% of NSEL.

Former MCX chief executive Shreekant Javalgekar was also arrested on Wednesday, taking the total number of arrests in the case to 11. Shah and Javalgekar will be produced in court on Thursday, 8 May 2014. MCX is also an affiliate of FTIL.

In a statement to BSE, FTIL acknowledged that its chairman has been arrested without offering any further comment.

As on 31 March 2013, promoters held 45.63% of FTIL.

The crisis at NSEL came to light on 31 July 2013 when the exchange suspended trading in all but its e-series contracts. These, too, were suspended a week later. The suspension may have been prompted by an instruction from the ministry of consumer affairs to the exchange asking it not to offer futures contracts. A spot exchange is not supposed to do so, but NSEL was doing that. NSEL tried to implement the change, but because its appeal was to investors and members who were not interested in spot trades, it eventually had to suspend all trading.

Subsequent investigations have highlighted the possibility of fraud and, according to the FMC, the involvement of promoters. On 14 August 2013, NSEL proposed a payout plan, but it has been unable to stick to the schedule and has not made a single successful payout ever since.

Forward Markets Commission (FMC) in its order dated 17 December 2013 said that FTIL, the promoter and anchor shareholder holding 26% of the paid-up capital of the commodity exchange MCX, is not 'fit and proper person' to continue to be a shareholder of 2% or more of the paid-up equity capital of MCX as prescribed under the guidelines issued by the Government of India (GoI) for capital structure of commodity exchanges post 5-years of operation.